Anti-neutrophil cytoplasmic antibodies (ANCA) is autoantibodies characteristic of vasculitis diseases. A connection between ANCA and Wegener's granulomatosis was well established. The interaction of both ANCA phenotypes (PR3-ANCA and MPO-ANCA) with leukocytes provoked cell activation, which might be involved in the pathogenesis of ANCA-related Wegener's granulomatosis.
In this study, we examined whether PR3-ANCA sera and purified immunoglobulins from patients with Wegener's granulomatosis prime human monocytic cells for enhanced responses to microbial components in terms of production of proinflammatory cytokines.
Flow cytometry demonstrated that stimulation with antibodies to proteinase 3 enhanced the expression of TLR2, 3, 4, 7, and 9, NOD1, and NOD2 in human mononuclear cells. The sera and purified immunoglobulins significantly primed human mononuclear cells to secrete interleukin-8 in response to microbial components via TLRs and NODs. Priming effects were also observed for the production of interleukin-6, monocyte chemoattractant protein-1, and tumor necrosis factor-α. On the other hand, PR3-ANCA-negative sera from patients with polyarteritis nodosa which possibly related to MPO-ANCA and aortitis syndrome as well as control sera from a healthy volunteer did not have any priming effects on PBMCs.
In conclusion, PR3-ANCA prime human mononuclear cells to produce cytokines upon stimulation with various microbial components by up-regulating the TLR and NOD signaling pathway, and these mechanisms may partially participate in the inflammatory process in Wegener's granulomatosis.
Anti‐neutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) are highly specific for Wegener's granulomatosis (WG). Evidence for a pivotal role of PR3‐ANCA in the induction of vasculitis has been demonstrated. B cell clusters have been observed within endonasal biopsy specimens.
To determine whether B cell selection and maturation take place in granulomatous lesions of WG.
Granulomatous lesions and the immunoglobulin (VH) gene repertoire from nasal tissue of six WG patients—two active and two smouldering localised WG (ANCA negative, restricted to respiratory tract), plus one active and one smouldering PR3‐ANCA positive generalised WG—were characterised by immunohistochemistry, polymerase chain reaction, cloning, DNA sequencing and database comparison.
B lymphocyte‐rich, follicle‐like areas were observed proximal to PR3 positive cells and plasma cells in granulomatous lesions; 184 VH genes from these granulomatous lesions were compared with 84 VH genes from peripheral blood of a healthy donor. The mutational pattern of VH genes from active WG resembled memory B cells. Structural homologies of VH genes from granulomatous lesions to PR3‐ANCA encoding genes were detected. Significantly more genes (55%, 45%, and 53%, respectively) from active WG compared with the healthy repertoire carried mutations to negatively charged amino acids within the binding site coding regions, favouring affinity to the positively charged PR3.
Selection and affinity maturation of potentially PR3‐ANCA producing autoreactive B cells may start in granulomatous lesions, thereby contributing to disease progression from ANCA negative localised to PR3‐ANCA positive generalised WG.
B lymphocyte; Wegener's granulomatosis; PR3; PR3‐ANCA; VH genes
Subacute bacterial endocarditis (SBE) occasionally exhibits positive cytoplasmic anti-neutrophil cytoplasmic antibody (c-ANCA) of the anti-proteinase-3 (PR-3) type. Clinically, it mimics ANCA-associated vasculitis, such as Wegener's disease with glomerulonephritis. Lung abscesses are the most common manifestation of lung involvement. We herein report a case of culture-negative SBE strongly c-ANCA/PR3-positive accompanied by pulmonary involvement and glomerulonephritis. In this case, we took biopsies of both the lung and kidney, although renal biopsy is usually preferred over lung biopsy. The lung biopsy showed severe alveolar capillaritis, suggesting vasculitis consistent with polyangiitis. The renal biopsy revealed glomerulonephritis with a membranoproliferative pattern. To our knowledge, this is the first such reported case.
A 68-year-old Chinese male patient presented to our hospital with a fever, cough, chest pain, and recurrent peripheral edema. He had a past medical history significant for treated schistosomiasis 20 years previously. Physical examination revealed palpable purpura, mild hypertension, hepatosplenomegaly, and a holosystolic cardiac murmur (Levine 2/6). Echocardiography showed tricuspid valve vegetations with moderate to severe regurgitation. Serum c-ANCA/PR3 and cryoglobulin were strongly positive. Renal biopsy results indicated membranoproliferative glomerulonephritis with several crescents. Chest CT revealed multiple intraparenchymal and subpleural nodules, and lung biopsy showed polyangiitis. The patient’s ANCA titers, glomerulonephritis, and pulmonary injury all resolved after antibiotic therapy.
SBE may present with positive c-ANCA/PR3, multiple pulmonary nodules, pulmonary polyangiitis, and glomerulonephritis clinically mimicking granulomatosis with polyangiitis (Wegener's granulomatosis).
Subacute bacterial endocarditis; PR3/c-ANCA; Granulomatosis with polyangiitis (Wegener's granulomatosis); Glomerulonephritis
Granulomatosis with polyangiitis, also known as Wegener’s granulomatosis, is a chronic systemic inflammatory disease that can also involve the eyes. We report a case of massive retinal and preretinal hemorrhages with perivascular changes as the initial signs in granulomatosis with polyangiitis (Wegener’s granulomatosis).
A 39-year-old Caucasian male presented with blurred vision in his right eye, myalgia and arthralgia, recurrent nose bleeds and anosmia. Fundus image of his right eye showed massive retinal hemorrhages and vasculitis-like angiopathy, although no fluorescein extravasation was present in fluorescein angiography. Laboratory investigations revealed an inflammation with increased C-reactive protein, elevated erythrocyte sedimentation rate and neutrophil count. Tests for antineutrophil cytoplasmic antibodies (ANCA) were positive for c-ANCA (cytoplasmatic ANCA) and PR3-ANCA (proteinase 3-ANCA). Renal biopsy demonstrated a focal segmental necrotizing glomerulonephritis. Granulomatosis with polyangiitis (Wegener’s granulomatosis) was diagnosed and a combined systemic therapy of cyclophosphamide and corticosteroids was initiated. During 3 months of follow-up, complete resorption of retinal hemorrhages was seen and general complaints as well as visual acuity improved during therapy.
Vasculitis-like retinal changes can occur in Wegener’s granulomatosis. Despite massive retinal and preretinal hemorrhages that cause visual impairment, immunosuppressive therapy can improve ocular symptoms.
Granulomatosis with polyangiitis; Wegener’s granulomatosis; Retinal vasculitis; Hemorrhages; Cyclophosphamide
A retrospective analysis was conducted of eight cases of Wegener's granulomatosis (WG), who presented with cutaneous lesions. The clinical, immunopathologic and histopathologic features of the cutaneous lesions were reviewed. Antineutrophil cytoplasmic antibody (ANCA) status of the patients was established. When possible, a comparison of immunofluorescence findings of skin biopsies was made with those of renal biopsies taken at the same time. In all except one, systemic and cutaneous disease developed concurrently. On histopathology, leukocytoclastic vasculitis was noted in five patients and features of lupus erythematosus and pyoderma gangrenosum in one case each. Four patients showed immunoglobulin deposits in subepidermal blood vessel walls, while one patient showed granular immune deposits at dermo-epidermal junction only. Immunoglobulin G was the most common immunoreactant detected. C-ANCA/proteinase 3 (PR3)-ANCA was positive in six patients, P-ANCA/myeloperoxidase (MPO)-ANCA in one patient, while one patient did not show ANCA positivity on indirect immunofluorescence. All four renal biopsies showed pauci-immune glomerulonephritis, irrespective of the presence (n=3) or absence (n=1) of immune deposits in the skin biopsy. Skin manifestations are encountered in nearly half of the patients with WG, thus it is important to be familiar with cutaneous histopathologic as well as immunofluorescence findings in WG patients.
Cutaneous biopsy; direct immunofluorescence; pauci-immune
Wegener's granulomatosis (WG) also known as granulomatosis with polyangiitis (GPA) is an anti-neutrophil cytoplasmic antibody-positive (ANCA) vasculitis which most commonly affects the upper respiratory tract, lungs and kidneys. It is uncommon for colitis to be the primary reason for the first hospital admission related to WG. This case represents one of the few in the literature where colitis is associated with WG and in particular, where colonic involvement was the presenting symptom. The patient presented to hospital with a 3-day history of bloody diarrhoea and was treated for colitis. The disease progressed and during the second admission renal and pulmonary involvement was found. A renal biopsy showed a crescentic change and a CT-confirmed inflammatory changes in the caecum and ascending colon. A diagnosis of WG was made and appropriate treatment initiated. The patient is now in remission.
BACKGROUND--Reports from specialist nephrological centres have suggested that the antineutrophil cytoplasm antibody (ANCA) test is highly specific and sensitive for patients with Wegener's granulomatosis. To determine the usefulness of the ANCA test in everyday respiratory practice the results of the test were audited in all patients in the south west of England with respiratory symptoms who underwent the test. METHODS--The results of all 335 patients who had presented with upper or lower respiratory tracts symptoms, or both, and were tested for ANCA by the indirect ANCA test in 1990, as recommended in the broadsheet of the British Association of Clinical Pathologists, were audited. Case notes and necropsy reports were available for review in 231 cases (69%), and in the remainder information was obtained by a standard questionnaire. RESULTS--There were 106 positive results, 45 (44%) from patients with Wegener's granulomatosis. The sensitivity and specificity of a positive ANCA test result in this study were 65% and 77% respectively. For a diagnosis of Wegener's granulomatosis the sensitivity and positive predictive accuracy of a positive cytoplasmic ANCA (c-ANCA) test were greater than of a positive perinuclear ANCA (p-ANCA) test. There were 61 positive tests in 266 patients who did not have Wegener's granulomatosis (23%); of these 27 were from patients with infection, 10 with fibrotic lung disease, nine with underlying connective tissue disease, seven with malignancy, and five following pulmonary emboli. Most of these positive ANCA results were p-ANCA (69%) rather than c-ANCA (31%). Serial ANCA requests were made in 15 cases of patients without Wegener's granulomatosis who had an initial positive ANCA test result. In all cases the ANCA tests subsequently became negative. CONCLUSIONS--In this study the sensitivity and specificity of a positive ANCA test result were less than that reported from specialised centres. However, the test was found to be useful in clinical practice, especially c-ANCA, in conjunction with clinical symptoms of respiratory pathology and evidence of renal disease.
Wegener’s Granulomatosis is a condition associated with systemic vasculitis which can present with upper respiratory tract symptoms initially. On September 2001, a 15-year-old girl presented with symptoms of nasal block for 3 weeks. She later developed joint pains and worsening renal status requiring dialysis. A renal biopsy was performed which showed pauci-immune cresentric glomerulonephritis. Her cANCA levels were positive. She was treated with oral cyclophosphamide and steroids and later responded.
Wegener granulomatosis; Young girl; Cyclophophamide; cANCA
Granulomatosis with polyangiitis (GPA), formerly known as Wegener’s granulomatosis (WG), belongs to the group of ANCA-associated necrotizing vasculitides. This study describes the clinical picture of the disease in a large cohort of GPA paediatric patients.
Children with age at diagnosis ≤ 18 years, fulfilling the EULAR/PRINTO/PRES GPA/WG classification criteria were extracted from the PRINTO vasculitis database. The clinical signs/symptoms and laboratory features were analysed before or at the time of diagnosis and at least 3 months thereafter and compared with other paediatric and adult case series (>50 patients) derived from the literature.
The 56 children with GPA/WG were predominantly females (68%) and Caucasians (82%) with a median age at disease onset of 11.7 years, and a median delay in diagnosis of 4.2 months. The most frequent organ systems involved before/at the time of diagnosis were ears, nose, throat (91%), constitutional (malaise, fever, weight loss) (89%), respiratory (79%), mucosa and skin (64%), musculoskeletal (59%), and eye (35%), 67% were ANCA-PR3 positive, while haematuria/proteinuria was present in > 50% of the children. In adult series, the frequency of female involvement ranged from 29% to 50% with lower frequencies of constitutional (fever, weight loss), ears, nose, throat (oral/nasal ulceration, otitis/aural discharge), respiratory (tracheal/endobronchial stenosis/obstruction), laboratory involvement and higher frequency of conductive hearing loss than in this paediatric series.
Paediatric patients compared to adults with GPA/WG have similar pattern of clinical manifestations but different frequencies of organ involvement.
Wegener’s granulomatosis; Granulomatosis with polyangiitis; Clinical study; Clinical picture of disease; Comparison with literature
Wegener’s granulomatosis (WG) is a multisystemic necrotising granulomatous vasculitis of small and medium sized vessels, that primarily involves the upper and lower respiratory tracts, lung tissues and kidneys. Serum antineutrophil cytoplasmic antibodies (ANCA) are a sensitive and specific marker of WG. Whereas the peripheral nervous system is often involved in WG, central nervous system manifestations are reported only in 2–8%, and are rarely present at onset. We report on a patient with atypical neurological presentation of ANCA negative WG in whom the diagnosis was made only after a meningeal biopsy.
Wegener’s granulomatosis (WG) is a necrotizing granulomatous vasculitis characterized by the involvement of the upper or lower airways, lungs, and kidneys, but it can affect almost any organ including the orbit. WG is rare in childhood. This case report describes a 7-year-old girl who presented bilateral idiophatic orbital inflammation and antineutrophil cytoplasmic antibodies-negative titres. Computed tomography scan and magnetic resonance imaging showed enlargement of both lacrimal glands with infiltration. Treatment with corticosteroids achieved remission of the disease. Three years later, she developed a systemic affectation with tracheal stenosis, pulmonary affectation, renal failure, and respiratory tract mucosa inflammation. Lacrimal gland biopsy showed perivascular nonspecific granulomas and ANCA titres remain negative. Treatment with corticosteroids and cyclophosphamide was done. A relapse occurred 2 years later, with complete remission with antitumor necrosis factor-alpha. No other symptoms have appeared after 9 years of follow-up. Early diagnosis and treatment is crucial to increase the survival rate in these patients.
ANCA; children; idiopathic orbital inflammation; exophthalmos; vasculitis; Wegener’s granulomatosis
Anti–neutrophil cytoplasmic antibodies (ANCAs) targeting proteinase 3 (PR3) have a high specifity for Wegener's granulomatosis (WG), and their role in activating leukocytes is well appreciated. In this study, we investigated the influence of PR3-ANCA and murine monoclonal antibodies on human umbilical vascular endothelial cells (HUVECs). Priming of HUVECs with tumor necrosis factor α induced endothelial upregulation of PR3 message and surface expression of this antigen, as measured by Cyto-ELISA, with a maximum occurrence after 2 h. Primed cells responded to low concentrations of both antibodies (25 ng–2.5 μg/ml), but not to control immunoglobulins, with pronounced, dose-dependent phosphoinositide hydrolysis, as assessed by accumulation of inositol phosphates. The signaling response peaked after 20 min, in parallel with the appearance of marked prostacyclin and platelet-activating factor synthesis. The F(ab)2 fragment of ANCA was equally potent as ANCA itself. Disrupture of the endothelial F-actin content by botulinum C2 toxin to avoid antigen–antibody internalization did not affect the response. In addition to the metabolic events, anti-PR3 challenge, in the absence of plasma components, provoked delayed, dose-dependent increase in transendothelial protein leakage. We conclude that anti-PR3 antibodies are potent inductors of the preformed phosphoinositide hydrolysis–related signal tranduction pathway in human endothelial cells. Associated metabolic events and the loss of endothelial barrier properties suggest that anti-PR3–induced activation of endothelial cells may contribute to the pathogenetic sequelae of autoimmune vasculitis characterizing WG.
Rheumatoid arthritis has varied pleuroparenchymal manifestations. Wegener's granulomatosis can develop in an established case of rheumatoid arthritis and this association although previously reported is very rare.
A 60-year-old lady had been diagnosed with rheumatoid arthritis on the basis of her clinical symptoms and serological tests which were positive RA factor and anti-CCP antibodies. Her rheumatoid arthritis activity had been mild and well controlled with hydroxychloroquine and low dose prednisone. She presented with a productive cough and right-sided pleuritic chest pain. CT scan of the chest showed three lung nodules with increased uptake on PET CT scan, raising concerns for an inflammatory or malignant process. The differential diagnosis included rheumatoid nodules, infections or malignancy. A CT-guided needle biopsy of the largest nodule was undertaken which showed vasculitis typical of Wegener's granulomatosis. Stains and cultures of the biopsy specimen were negative for bacteria, fungi and acid fast bacilli. A panel of serological tests for vasculitis were checked and showed elevated titers of cANCA and anti-proteinase 3 antibodies. Urine analysis and CT scan of paranasal sinuses was normal. Since the upper respiratory tract and the kidneys were spared a diagnosis of limited Wegener's granulomatosis affecting only the lungs was made. Due to the toxicity of cyclophosphamide, her relatively mild disease sparing the kidneys and the underlying rheumatoid arthritis, weekly methotrexate was started and low dose prednisone was continued. She had marked symptomatic improvement and complete resolution of the nodules was documented on subsequent imaging.
Wegener's granulomatosis developing in a patient with rheumatoid arthritis is very rare but should be considered as it warrants a different and possibly more aggressive treatment approach.
The use of serum antibodies to neutrophil cytoplasmic antigens (ANCA) as a diagnostic marker for Wegener's granulomatosis and other forms of vasculitis has been assessed. Although ANCA have been described by several groups the precise antigenic targets are unknown, and detection of ANCA still relies on an indirect immunofluorescence assay technique. Several different patterns of fluorescence have been produced by using sera from different groups of patients, and insufficient information is available on the frequency of positive results and of the patterns of immunofluorescence obtained when serum from patients with vasculitis as a part of a generalised connective tissue disease is used. A study was carried out on serum from 240 patients, including 23 patients with Wegener's granulomatosis, 12 with microscopic polyarteritis, and 30 with various connective tissue diseases. Three patterns of fluorescence were observed: bright coarsely granular cytoplasmic, bright non-granular cytoplasmic, and weak diffuse cytoplasmic. The bright, coarsely granular pattern was 86% specific for Wegener's granulomatosis in this series and was observed in 18 of 23 cases. Other patterns of fluorescence were found in various conditions and were not of diagnostic value. The technique is simple, inexpensive, rapid, and reproducible.
Wegener’s granulomatosis (WG) is a systemic disease with a complex genetic background. It is characterised by inflammation of the small blood vessels leading to damage in any number of organs. The common features include granulomatous inflammation of the respiratory tract and kidneys. Most patients have measurable autoantibodies against neutrophil proteinase-3 (Antineutrophil Cytoplasmic Antibody, ANCA). Pituitary involvement is a rare complication of this disease and, when it occurs, diabetes insipidus is the most common manifestation. We describe a 38-year-old female with known long-term WG who presented with partial hypopituitarism, severe malnutrition and ANCA negative status, with a favourable response to steroid pulse therapy.
There are only a few reported cases about spinal cord involvement with Wegener’s granulomatosis (WG) in the literature. In these cases, the spinal cord is usually indented or compressed by dural and meningeal masses which are characterized by necrotizing granuloma formation and vasculitis. And, it usually cannot be correctly diagnosed. A 53-year-old woman suffered from Wegener’s granulomatosis, in whom the upper thoracic spinal cord compression is the initial manifestation. The surgical biopsy and thoracic laminectomy were performed and the histologic examination was done. This patient was finally diagnosed as WG when the pathologic examination revealed as Wegener’s granulomatosis and the serum antineutrophil cytoplasmic antibodies (ANCA) were reported positive; titers of antimyeloperoxidase (MPO) antibodies were markedly elevated. After treatment with cyclophosphamide and corticosteroids this patient partially recovered from neurological involvement. In a case such as this, careful monitoring of clinical parameters is essential for assessing disease activity with repeated MRI if neurologic status changes. Serial measurement of ANCA titers may also be helpful to establish the diagnosis. Cyclophosphamide and corticosteroids are the agents of choice for induction of remission of WG.
Spinal cord; Wegener’s granulomatosis; Vasculitis
Wegener's Granulomatosis and Microscopic Polyangiitis are life-threatening systemic necrotizing vasculitides of unknown aetiology. The appearance of circulating antibodies to neutrophil cytoplasmic antigens (ANCA) is strongly associated with the development of the disease. A link between infection and disease has long been suspected, and the appearance of ANCA antibodies has been reported following bacterial and viral infections. The depletion of circulating B cells with monoclonal antibody therapy can induce remission, and this observation suggests a pathogenic role for B cells in this disease. As bacterial DNA is known to induce B cell proliferation and antibody production via TLR-9 stimulation, we have explored the possibility that unmethylated CpG oligodeoxynucleotide, as found in bacterial and viral DNA, may play a role in stimulating circulating autoreactive B cells to produce ANCA in patients with vasculitis.
We have confirmed that unmethylated CpG oligonucleotide is a potent stimulator of antibody production by PBMC in vitro. The stimulation of PBMC with CpG oligonucleutides resulted in the production of similar amounts of IgG in both ANCA+ patients and normal controls. In spite of this, PR3 ANCA+ patients synthesised significantly higher amount of IgG ANCA than normal controls. In MPO ANCA+ patients, there was a tendency for patients to produce higher amount of ANCA than controls, however, the difference did not reach significance. Furthermore, we were able to detect circulating MPO-reactive B cells by ELISpot assay from the peripheral blood of 2 MPO+ ANCA vasculitis patients. Together, this indicates that circulating anti-neutrophil autoreactive B cells are present in ANCA+ vasculitis patients, and they are capable of producing antibodies in response to CpG stimulation. Of note, CpG also induced the production of the relevant autoantibodies in patients with other types of autoimmune diseases.
Circulating ANCA autoreactive B cells are present in patients with ANCA+ vasculitis. The production of ANCA from these cells in response to unmethylated CpG stimulation lead us to propose that stimulation of these cells by immunostimulatory DNA sequences such as CpG oligodeoxynucleotide during infection may provide a link between infection and ANCA associated vasculitis. This phenomenon may also apply to other antibody mediated autoimmune diseases.
The glycosylation status of autoantigens appears to be crucial for the pathogenesis of some autoimmune diseases, since carbohydrates play a crucial role in the distinction of self from non-self. Proteinase 3 (PR3), the main target antigen for anti-neutrophil cytoplasmic antibodies (ANCA) in patients with Wegener’s granulomatosis (WG), contains two Asn-linked glycosylation sites. The present study explores the influence of the glycosylation status of PR3 on the PR3 recognition by ANCA in a well characterized population of patients with WG.
Forty-four patients with WG (459 serum samples) who participated in a multicenter randomized trial, were tested by capture ELISA for ANCA against PR3 and deglycosylated recombinant variants of PR3.
The patients were followed for a median of 27 months, and the median number of serum samples per patient was 10. At baseline, the correlation between the levels of ANCA against PR3 and against all the deglycosylated recombinant variants of PR3 were greater than 0.94 (ρ<0.001 for all the comparisons). Longitudinal analyses comparing the levels of ANCA against PR3 versus all the deglycosylated recombinant variants of PR3, using linear mixed models, showed no significant statistical differences (ρ≥0.90 in all cases).
The glycosylation status of PR3 has no impact on its recognition by ANCA in WG.
ANCA; biological markers; glycosylation; proteinase 3; Wegener’s granulomatosis
Wegener’s granulomatosis, also known as anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, is a small vessel vasculitis with primarily pulmonary, renal, and sinus disease manifestations. The prevalence of Wegener’s granulomatosis is three cases per 100,000 patients. Cardiovascular, neurologic, cutaneous, and joint manifestations have been reported in many case reports and case series. Gastrointestinal manifestations are less noted in Wegener’s granulomatosis, although they have been previously reported in the form of intestinal perforation and intestinal ischemia. Additionally, there are characteristic findings of vasculitis that are noted with active Wegener’s granulomatosis of the small bowel. We report a case of an elderly patient who presented with weight loss, diarrhea, and hematochezia. His symptoms were chronic and had lasted for more than 1 year before diagnosis. Inflammatory bowel disease or chronic enteritis due to Salmonella arizonae because of reptile exposure originally were suspected as etiologies of his presentation. The findings of proteinuria, renal failure, and pauci-immune glomerulonephritis on renal biopsy, in conjunction with an elevated c-ANCA titer, confirmed the diagnosis of Wegener’s granulomatosis with associated intestinal vasculitis. This case demonstrates an atypical presentation of chronic duodenitis and jejunitis secondary to Wegener’s granulomatosis, which mimicked inflammatory bowel disease.
ANCA-associated vasculitis; Wegener’s syndrome; pauci-immune glomerulonephritis; Salmonella arizonae; inflammatory bowel disease
Eosinophilic granulomatosis with polyangiitis (EGPA) is a multisystemic disorder, belonging to the small vessel anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, defined as an eosinophil-rich and necrotizing granulomatous inflammation often involving the respiratory tract, and necrotizing vasculitis predominantly affecting small to medium-sized vessels, associated with asthma and eosinophilia. EGPA pathogenesis is not well known: HLA-DRB1*04 and *07, HLA-DRB4 and IL10.2 haplotype of the IL-10 promoter gene are the most studied genetic determinants. Among the acquired pathogenetic factors, the exposure to different allergens, infections, vaccinations, drugs, and silica exposure have been involved. Eosinophils are the most characteristic cells in EGPA and different studies have demonstrated their role as effector and immunoregulatory cells. EGPA is considered as a disease with a prevalent activation of the Th-2 cellular-mediated inflammatory response and also humoral immunity plays an important role. A link between B and T inflammatory responses may explain different disease features. EGPA typically develops into three sequential phases: the allergic phase, distinguished by the occurrence of asthma, allergic rhinitis, and sinusitis, the eosinophilic phase, in which the main pathological finding is the eosinophilic organ infiltrations (e.g., lungs, heart, and gastrointestinal system), and the vasculitic phase, characterized by purpura, peripheral neuropathy, and constitutional symptoms. ANCA (especially pANCA anti-myeloperoxidase) are present in 40–60% of the patients. An elevation of IgG4 is frequently found. Corticosteroids and cyclophosphamide are classically used for remission induction, while azathioprine and methotrexate are the therapeutic options for remission maintenance. B-cell depletion with rituximab has shown promising results for remission induction.
eosinophilic granulomatosis with polyangiitis; vasculitis; eosinophils; vascular diseases; ANCA-associated vasculitis
Purpose of Review
Anti-neutrophil cytoplasmic autoantibodies (ANCA) are associated with vasculitis. Current therapy involves administration of toxic therapy that is not optimally effective. The review will summarize evidence for the pathogenicity of ANCA, which will suggest possible strategies for improving treatment.
Pauci-immune small vessel vasculitis is associated with antibodies against myeloperoxidase (MPO-ANCA) and proteinase 3 (PR3-ANCA). One research group has reported a high frequency of autoantibodies against lysosomal-associated membrane protein 2 (LAMP-2) in patients with MPO-ANCA or PR3-ANCA. Epigenetic dysregulation appears to be the basis for increased MPO and PR3 neutrophil gene expression in ANCA disease. Release of neutrophil extracellular traps (NETS) may be involved in initiating the ANCA autoimmune response and causing vessel injury. Generation of C5a by alternative pathway activation is involved in pathogenesis in mouse models. Intervention strategies in mice that target antigens, antibodies and inflammatory signaling pathways may translate into novel therapies. Animal models of LAMP-ANCA and PR3-ANCA disease have been proposed. Molecular mimicry and responses to complementary peptides may be initiating events for ANCA. T cells, including regulatory T cells, have been implicated in the origin and modulation of the ANCA, as well as in the induction of tissue injury.
Our basic understanding of the origins and pathogenesis of ANCA disease is advancing. This deeper understanding already has spawned novel therapies that are being investigated in clinical trials. This brief review shows that there are more questions than answers, and new questions are emerging faster than existing questions are being answered.
Vasculitis; Pathogenesis; Antineutrophil Cytoplasmic Autoantibodies; ANCA
Antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis is a severe condition encompassing two major syndromes: granulomatosis with polyangiitis (formerly known as Wegener’s granulomatosis) and microscopic polyangiitis. Its cause is unknown, and there is debate about whether it is a single disease entity and what role ANCA plays in its pathogenesis. We investigated its genetic basis.
A genomewide association study was performed in a discovery cohort of 1233 U.K. patients with ANCA-associated vasculitis and 5884 controls and was replicated in 1454 Northern European case patients and 1666 controls. Quality control, population stratification, and statistical analyses were performed according to standard criteria.
We found both major-histocompatibility-complex (MHC) and non-MHC associations with ANCA-associated vasculitis and also that granulomatosis with polyangiitis and microscopic polyangiitis were genetically distinct. The strongest genetic associations were with the antigenic specificity of ANCA, not with the clinical syndrome. Anti–proteinase 3 ANCA was associated with HLA-DP and the genes encoding α1-antitrypsin (SERPINA1) and proteinase 3 (PRTN3) (P = 6.2×10−89, P = 5.6×10−12, and P = 2.6×10−7, respectively). Anti–myeloperoxidase ANCA was associated with HLA-DQ (P = 2.1×10−8).
This study confirms that the pathogenesis of ANCA-associated vasculitis has a genetic component, shows genetic distinctions between granulomatosis with polyangiitis and microscopic polyangiitis that are associated with ANCA specificity, and suggests that the response against the autoantigen proteinase 3 is a central pathogenic feature of proteinase 3 ANCA–associated vasculitis. These data provide preliminary support for the concept that proteinase 3 ANCA–associated vasculitis and myeloperoxidase ANCA–associated vasculitis are distinct autoimmune syndromes. (Funded by the British Heart Foundation and others.)
The limited form of Granulomatosis with Polyangiitis (GPA), formerly known as Wegener’s Granulomatosis (WG) primarily involves the head and neck region, including the orbit, but is often a diagnostic challenge, particularly as it commonly lacks positive anti-neutrophil cytoplasm antibody (ANCA) titres or classical features on diagnostic orbital biopsies. The purpose of this study was to relate biopsy findings with clinical outcome and to determine which histopathological features are predictive of a clinical diagnosis of GPA.
Retrospective case series of 234 patients identified from the database of the UCL Institute of Ophthalmology Department of Eye Pathology as having had orbital biopsies of orbital inflammatory disorders performed between 1988 and 2009. Clinical records were obtained for the patients and analysed to see whether patients had GPA or not, according to a standard set of diagnostic criteria (excluding any histopathological findings). Biopsy features were then correlated with the clinical diagnosis in univariate and multivariate analyses to determine factors predictive of GPA.
Of the 234 patients, 36 were diagnosed with GPA and 198 with other orbital pathologies. The majority of biopsies were from orbital masses (47%). Histology showed a range of acute and chronic inflammatory pictures in all biopsies, but the presence of neutrophils (P<0.001), vasculitis (P<0.001), necrosis (P<0.001), eosinophils (P<0.02) and macrophages (P=0.05) were significantly associated with a later clinical diagnosis of GPA. In a multivariate analysis, only tissue neutrophils (OR=3.6, P=0.01) and vasculitis (OR=2.6, P=0.02) were independently associated with GPA, in contrast to previous reports associating eosinophils and necrosis with the diagnosis.
Neutrophil, eosinophil and macrophage infiltration of orbital tissues, together with vasculitis and necrosis, are all associated with a clinical diagnosis of GPA, but only neutrophil infiltration and vasculitis are independently associated with this diagnosis. These features may assist in the establishing the diagnosis of limited GPA among patients with early orbital disease, particularly in the absence of positive serum ANCA titres.
Granulomatosis with polyangiitis; histopathology; eosinophils; nuclear dust
Clinical and serological profiles of idiopathic and drug-induced autoimmune diseases can be very similar. We compared data from idiopathic and antithyroid drug (ATD)-induced antineutrophil cytoplasmic antibody (ANCA)-positive patients. From 1993 to 2003, 2474 patients were tested for ANCA in the Laboratory for Allergy and Clinical Immunology in Belgrade. Out of 2474 patients, 72 (2.9%) were anti-proteinase 3 (PR3)- or anti-myeloperoxidase (MPO)-positive and their clinical and serological data were analyzed. The first group consisted of ANCA-associated idiopathic systemic vasculitis (ISV) diagnosed in 56/72 patients: 29 Wegener's granulomatosis (WG), 23 microscopic polyangiitis (MPA) and four Churg-Strauss syndrome. The second group consisted of 16/72 patients who became ANCA-positive during ATD therapy (12 receiving propylthiouracil and four receiving methimazole). We determined ANCA and antinuclear (ANA) antibodies by indirect immunofluorescence; PR3-ANCA, MPO-ANCA, anticardiolipin (aCL) and antihistone antibodies (AHA) by ELISA; and cryoglobulins by precipitation. Complement components C3 and C4, alpha-1 antitrypsin (α1 AT) and C reactive protein (CR-P) were measured by nephelometry. Renal lesions were present in 3/16 (18.8%) ATD-treated patients and in 42/56 (75%) ISV patients (p <0.001). Skin lesions occurred in 10/16 (62.5%) ATD-treated patients and 14/56 (25%) ISV patients (p <0.01). ATD-treated patients more frequently had MPO-ANCA, ANA, AHA, aCL, cryoglobulins and low C4 (p <0.01). ISV patients more frequently had low α1 AT (p = 0.059) and high CR-P (p <0.001). Of 16 ATD-treated patients, four had drug-induced ANCA vasculitis (three MPA and one WG), while 12 had lupus-like disease (LLD). Of 56 ISV patients, 13 died and eight developed terminal renal failure (TRF). There was no lethality in the ATD-treated group, but 1/16 with methimazole-induced MPA developed pulmonary-renal syndrome with progression to TRF. ANCA-positive ISV had a more severe course in comparison with ATD-induced ANCA-positive diseases. Clinically and serologically ANCA-positive ATD-treated patients can be divided into two groups: the first consisting of patients with drug-induced WG or MPA which resemble ISV and the second consisting of patients with LLD. Different serological profiles could help in the differential diagnosis and adequate therapeutic approach to ANCA-positive ATD-treated patients with symptoms of systemic disease.
Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis (WG), is a rare systemic vasculitis that classically manifests as necrotizing granulomas of the upper and lower respiratory tract, kidneys, and blood vessels; however, it may affect any organ system, including the skin. Cutaneous manifestations occur in up to 45% of patients during the disease course, and are the presenting feature in 9% to 14% of patients. The most common skin lesion specific to GPA is palpable purpura, with the histopathologic correlate of leukocytoclastic vasculitis. However, a wide range of clinical and histologic features may be seen. We herein report a case of a previously healthy 52-year-old Caucasian man who presented with multiple progressively enlarging painful ulcers on his face, upper extremities, back, and abdomen over a two-month period. Skin biopsies revealed pyoderma gangrenosum-like features. Serological tests were positive for PR3/c-ANCA. Six months later, the patient developed recurrent episodes of sinusitis associated with nasal bleeds and eventually nasal septum perforation. Despite aggressive treatment with Cyclophosphamide and steroids over one year, the patient had persistent nonhealing large ulcers and developed multiple lung nodules with cavitary lesions.